LOANS - Loans by Class Modified as Troubled Debt Restructurings (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019 USD ($) contract	Sep. 30, 2018 USD ($) contract	Dec. 31, 2018 USD ($) contract
Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	33	30
Troubled debt restructurings principal balances	$ 4,983	$ 2,261
Purchased Loans By Class Modified
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	24	18
Troubled debt restructurings principal balances	$ 1,713	$ 1,865
Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings principal balances	$ 1,700	$ 1,900
Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	13	29
Troubled debt restructurings principal balances	$ 843	$ 1,736
Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	21	24
Troubled debt restructurings principal balances	$ 1,239	$ 2,371
Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	113		99
Troubled debt restructurings principal balances	$ 13,430		$ 9,323
Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	129		132
Troubled debt restructurings principal balances	$ 18,295		$ 18,740
Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	60		62
Troubled debt restructurings principal balances	$ 1,641		$ 1,754
Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	35		43
Troubled debt restructurings principal balances	$ 2,942		$ 3,451
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	3	10
Troubled debt restructurings principal balances	$ 550	$ 302
Commercial, financial and agricultural | Purchased Loans By Class Modified
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	1
Troubled debt restructurings principal balances	$ 0	$ 5
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1	4
Troubled debt restructurings principal balances	$ 3	$ 10
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1	0
Troubled debt restructurings principal balances	$ 1	$ 0
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	5		5
Troubled debt restructurings principal balances	$ 649		$ 256
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1		1
Troubled debt restructurings principal balances	$ 31		$ 31
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	13		14
Troubled debt restructurings principal balances	$ 119		$ 138
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	3		3
Troubled debt restructurings principal balances	$ 25		$ 32
Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	1
Troubled debt restructurings principal balances	$ 0	$ 3
Real estate – construction and development | Purchased Loans By Class Modified
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	0
Troubled debt restructurings principal balances	$ 0	$ 0
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	0
Troubled debt restructurings principal balances	$ 0	$ 0
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	0
Troubled debt restructurings principal balances	$ 0	$ 0
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	3		5
Troubled debt restructurings principal balances	$ 69		$ 145
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	4		4
Troubled debt restructurings principal balances	$ 878		$ 1,015
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1		1
Troubled debt restructurings principal balances	$ 1		$ 2
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	2		5
Troubled debt restructurings principal balances	$ 257		$ 293
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	2	1
Troubled debt restructurings principal balances	$ 224	$ 303
Real estate – commercial and farmland | Purchased Loans By Class Modified
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	1
Troubled debt restructurings principal balances	$ 0	$ 69
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	3	2
Troubled debt restructurings principal balances	$ 341	$ 548
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1	1
Troubled debt restructurings principal balances	$ 325	$ 69
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	12		12
Troubled debt restructurings principal balances	$ 2,788		$ 2,863
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	11		12
Troubled debt restructurings principal balances	$ 5,829		$ 6,162
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	3		3
Troubled debt restructurings principal balances	$ 530		$ 426
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	5		7
Troubled debt restructurings principal balances	$ 1,428		$ 1,685
Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	21	12
Troubled debt restructurings principal balances	$ 4,183	$ 1,617
Real estate – residential | Purchased Loans By Class Modified
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	20	16
Troubled debt restructurings principal balances	$ 1,674	$ 1,791
Real estate – residential | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	4	17
Troubled debt restructurings principal balances	$ 481	$ 1,155
Real estate – residential | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	17	23
Troubled debt restructurings principal balances	$ 895	$ 2,302
Real estate – residential | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	88		71
Troubled debt restructurings principal balances	$ 9,915		$ 6,043
Real estate – residential | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	113		115
Troubled debt restructurings principal balances	$ 11,557		$ 11,532
Real estate – residential | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	20		20
Troubled debt restructurings principal balances	$ 925		$ 1,119
Real estate – residential | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	18		24
Troubled debt restructurings principal balances	$ 1,178		$ 1,424
Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	7	6
Troubled debt restructurings principal balances	$ 26	$ 36
Consumer installment | Purchased Loans By Class Modified
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	4	0
Troubled debt restructurings principal balances	$ 39	$ 0
Consumer installment | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	5	6
Troubled debt restructurings principal balances	$ 18	$ 23
Consumer installment | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	2	0
Troubled debt restructurings principal balances	$ 18	$ 0
Consumer installment | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	5		6
Troubled debt restructurings principal balances	$ 9		$ 16
Consumer installment | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0		0
Troubled debt restructurings principal balances	$ 0		$ 0
Consumer installment | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	23		24
Troubled debt restructurings principal balances	$ 66		$ 69
Consumer installment | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	7		4
Troubled debt restructurings principal balances	$ 54		$ 17